JP2022101460A - Beneficiation method - Google Patents

Abstract

To provide a beneficiation method in which chalcopyrite and pyrite can be separated even for mineral slurries containing calcium.SOLUTION: A beneficiation method includes a mineral slurry production step of mixing a chalcopyrite and pyrite-containing mineral particle, calcium-containing water, and an iron source to yield a mineral slurry, a stirring step of stirring the mineral slurry, and an ore flotation step of performing ore floatation using the mineral slurry after the stirring step. The coexistence of calcium ion and iron ion suppresses the floating of pyrite. As a result, chalcopyrite and pyrite can be separated by ore flotation.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mineral processing method. More specifically, the present invention relates to a mineral processing method for separating chalcopyrite and pyrite.

The ores mined from the mine include useful minerals (minerals containing a large amount of target metal) and gangue minerals (minerals containing almost no target metal). Therefore, a mineral processing process is performed to recover useful minerals from the ore.

Generally, in the mineral processing, after crushing the ore to obtain a mixed powder of useful minerals and gangue minerals, the mineral processing utilizes the difference in physical properties such as specific density, magnetism, and hydrophilicity of each mineral species. It is carried out by separating (powder and granule products with an increased proportion of useful minerals) and tail ore (powder and granule products as unnecessary residue).

Froth flotation is known as a mineral processing process that utilizes the difference in hydrophilicity of each mineral species. Froth flotation is carried out by blowing air bubbles into the mineral slurry obtained by adding water to the mixed powder or granular material. Hydrophobic mineral particles adhere to bubbles and float, and hydrophilic mineral particles settle without adhering to bubbles. In order to improve the separation efficiency of flotation and sedimentation, it is common to add flotation agents such as catching agents, inhibitors and foaming agents to the mineral slurry.

Copper ore used for copper smelting includes chalcopyrite, which is a useful mineral, and pyrite, which is a gangue mineral. Therefore, it is required to separate chalcopyrite and pyrite by flotation. In flotation, which separates chalcopyrite and pyrite, chalcopyrite is floated and recovered as flotation. However, in the region of pH less than 10, it is difficult to separate chalcopyrite and pyrite because the catching agent also adheres to pyrite and easily floats.

Therefore, it is known that the mineral slurry is flotated as alkaline with a pH of 10 or higher. In the region of pH 10 or higher, a hydrophilic iron or calcium hydroxide film is formed on the pyrite surface, and the adhesion of the collecting agent is suppressed. In addition ^, OH- is exchanged with zansate ions on the surface of pyrite, and zansate, which is a type of catching agent, is removed. In addition, the surface of pyrite is oxidized and hydrophilicity is maintained. This suppresses the floating of pyrite.

However, in order to make the mineral slurry alkaline with a pH of 10 or more, a large amount of a pH adjusting agent such as lime is required, which increases the operating cost. Regarding this problem, Patent Document 1 discloses that by adding a sulfoxide reagent to a mineral slurry, the floating of sulfide-containing gangue minerals such as pyrite is suppressed without adjusting the pH.

Japanese Unexamined Patent Publication No. 2018-75575

According to the method of Patent Document 1, since it is not necessary to adjust the pH, the cost of the pH adjusting agent can be reduced. However, it is necessary to add a sulfoxide reagent. If the addition of the sulfoxide reagent becomes unnecessary, the cost can be further reduced.

In actual operation, seawater may be used to produce mineral slurries. Seawater contains calcium. When the mineral slurry is alkaline, CaCO ₃ is deposited on the surface of the mineral particles. Due to this, the separation efficiency of chalcopyrite and pyrite in flotation decreases.

In view of the above circumstances, it is an object of the present invention to provide a mineral processing method capable of separating chalcopyrite and pyrite even in a mineral slurry containing calcium.

The mineral processing method of the first invention comprises a mineral slurry manufacturing step of mixing mineral particles containing brass ore and pyrite, water containing calcium and an iron source to obtain a mineral slurry, a stirring step of stirring the mineral slurry, and the above-mentioned It is characterized by comprising a flotation beneficiation step of performing flotation beneficiation using the mineral slurry after the stirring step.
The mineral processing method of the second invention is characterized in that, in the first invention, the amount of the iron source added is such that the molar ratio of calcium ions to iron ions in the liquid phase of the mineral slurry is 1 to 10.
The beneficiation method of the third invention is characterized in that, in the first or second invention, the stirring time in the stirring step exceeds the time point at which the oxidation rate of pyrite changes from low speed to high speed.
The mineral processing method of the fourth invention is characterized in that, in the first or second invention, the stirring time in the stirring step is more than 150 minutes.
The mineral processing method of the fifth invention is characterized in that, in any one of the first to fourth inventions, the liquid phase of the mineral slurry in the stirring step is pH 6 to 9.

According to the present invention, the coexistence of calcium ions and iron ions suppresses the floating of pyrite. As a result, chalcopyrite and pyrite can be separated by flotation.

FIG. (A) is a graph showing the time change of Total-S concentration at pH 6. FIG. (B) is a graph showing the time change of the Total-S concentration in the case of pH 9. It is explanatory drawing of the flotation test.

Next, an embodiment of the present invention will be described.
The mineral processing method according to the embodiment of the present invention includes (1) a pretreatment step, (2) a mineral slurry production step, (3) a stirring step, and (4) a flotation beneficiation step. The mineral processing method of the present embodiment may include at least (2) a mineral slurry production step, (3) a stirring step, and (4) a flotation beneficiation step, and other steps may be omitted or added.

(1) Pretreatment step In the pretreatment step, ore is crushed and gangue is removed.
In general, copper ore contains useful minerals such as chalcopyrite (CuFeS ₂ ), mottled copper ore (bornite: Cu ₅ FeS ₄ ), arsenic arsenic (enargite: Cu ₃ AsS ₄ ), and bright copper ore (chalcocite: Cu ₂ S). ), Chalcopyrite (tennantite: (Cu, Fe, Zn) ₁₂ (Sb, As) ₄ S1 ₃ ), copper indigo (covellite: CuS), etc. are included. Further, the copper ore includes pyrite (pyrite: FeS ₂ ), arsenopyrite (FeAsS), quartz, long stone and the like as gangue minerals.

Crush the ore to obtain mineral particles. The particle size of the mineral particles is adjusted so that a single mineral can be obtained according to the size of the mineral contained in the ore. For example, in the case of chalcopyrite, it is generally adjusted to about 100 μm below the sieve. In actual operations using ores containing various minerals as raw materials, it is common to pulverize the ore to about 100 μm under a sieve and then adjust the particle size of the ore to the optimum conditions in consideration of flotation results and the like.

It is preferable to remove the gangue contained in the ore as needed. Various mineral processing methods such as flotation can be adopted for removing gangue. For example, bulk flotation separates sulfide minerals from other gangues. In bulk flotation, various sulfide minerals are blown by adding a flotation agent such as a catching agent, an inhibitor, and a foaming agent to a mineral slurry obtained by adding water to mineral particles (crushed ore). The gangue is settled and separated while floating together.

Sulfide minerals obtained by bulk flotation are called bulk flotations. The concentrate supplied to the next step may contain at least chalcopyrite and pyrite.

(2) Mineral slurry manufacturing step In the mineral slurry manufacturing step, mineral particles containing at least chalcopyrite and pyrite are mixed with water to obtain a mineral slurry. As the water used for producing the mineral slurry, water containing calcium such as seawater can be used. The calcium concentration of this water is, for example, 100 to 400 mg / L. Calcium chloride (CaCl ₂ ), calcium hydroxide (CaOH ₂ ) and the like can be used as the calcium source.

When calcium is contained in the liquid phase of the mineral slurry, CaCO ₃ is deposited on the surface of the mineral particles. Due to this, the separation efficiency between chalcopyrite and pyrite may decrease in the flotation in the subsequent process. In this respect, the inventors of the present application have obtained the finding that the decrease in separation efficiency can be suppressed by coexisting iron ions.

Therefore, an iron source is mixed in the production of the mineral slurry. As the iron source, ferric chloride (FeCl ₃ ), ferric sulfate (Fe ₂ (SO ₄ ) ₃ ), ferric nitrate (Fe (NO ₃ ) ₃ ) and the like can be used. By mixing an iron source with the mineral slurry, calcium ions and iron ions coexist in the aqueous phase of the mineral slurry.

The timing of adding the iron source is not particularly limited. After adding an iron source to water containing calcium, mineral particles may be added to produce a mineral slurry. An iron source may be added after mineral particles are added to calcium-containing water to produce a mineral slurry. Mineral particles, water containing calcium, and iron sources may be mixed at the same time.

Hereinafter, the molar ratio of calcium ions to iron ions in the liquid phase of the mineral slurry is referred to as “Ca / Fe”. The amount of the iron source added is preferably an amount in which Ca / Fe is 1 to 10.

The reason why the separation efficiency of chalcopyrite and pyrite is improved by the coexistence of iron ions is that the oxidation of the pyrite surface is promoted by the mechanisms represented by the following formulas A to C. Specifically, in the first stage of oxidation, the ferrous ore is oxidatively dissolved as shown in the formula A, and then the ferrous ion (Fe ²⁺ ) generated as shown in the formula B is oxidized and the ferric ion (Fe 2+) is oxidized. It becomes ³⁺ ) and acts as an oxidizing agent again as shown in the formula C, and the second stage oxidation of the yellow iron ore occurs. Therefore, the coexistence of ferric ion (Fe ³⁺ ) according to the present invention promotes the reaction of the formula C, that is, the oxidation of pyrite is promoted.
Formula (A): Reaction of O ₂ and FeS ₂ adsorbed on the surface (first-stage oxidative dissolution)
FeS ₂ + 7 / 2O ₂ + H ₂ O → Fe ^{2 +} + SO _4-2 + 2H ⁺
Equation (B): Oxidation of Fe ²⁺ by dissolved oxygen Fe ²⁺ + 1 / 4O ₂ + 4H ⁺ → Fe ³⁺ + 1 / 2H ₂ O
Formula (C): Reaction of the produced Fe ³⁺ and FeS ₂ (second-stage oxidative dissolution)
FeS ₂ + 14Fe ³⁺ + 8H ₂ O → 15Fe ²⁺ + 2SO ₄ ² + 16H ⁺

The pH of the liquid phase of the mineral slurry is preferably 6 to 7. Then, the precipitation of calcium can be suppressed. Therefore, the pH is adjusted by adding a pH adjuster to the mineral slurry as needed. The pH adjuster is not particularly limited, but sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca (OH) ₂ ), calcium carbonate (CaCO ₃ ) and the like can be used as the alkali. Hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ) and the like can be used as the acid.

(3) Stirring step In the stirring step, the mineral slurry is stirred. Stirring is performed, for example, by charging a mineral slurry into an open tank to the atmosphere and stirring with a stirrer. By stirring the mineral slurry, air is taken into the liquid phase and the dissolved oxygen concentration rises. Dissolved oxygen in the liquid phase oxidizes the surface of chalcopyrite and pyrite mineral particles.

The inventors of the present application analyzed the oxidation rates of chalcopyrite and pyrite, and obtained the following findings. That is, the oxidation rate of chalcopyrite is constant regardless of the passage of stirring time. On the other hand, the oxidation rate of pyrite is almost the same as the oxidation rate of chalcopyrite at the initial stage of stirring, but the oxidation rate becomes faster after a specific time has passed. That is, the oxidation rate of pyrite changes from low speed to high speed during stirring.

After the oxidation rate of pyrite changes at a high speed, pyrite can be made more oxidized than chalcopyrite. Moreover, the longer the stirring time, the greater the difference in the degree of oxidation between pyrite and chalcopyrite. Oxidation of pyrite produces hydrophilic ferric hydroxide on the surface of pyrite. In addition, this suppresses the adhesion of the catching agent to pyrite. Therefore, the hydrophilicity of pyrite is maintained, and the separation of chalcopyrite and pyrite becomes possible by the flotation in the next step.

Therefore, the stirring time of the mineral slurry is set to a time exceeding the time point at which the oxidation rate of pyrite changes from low speed to high speed (hereinafter referred to as the change time point). By stirring until the oxidation rate of pyrite becomes high, pyrite can be made more oxidized than chalcopyrite. This maintains the hydrophilicity of pyrite. Therefore, in the flotation step of the next step, chalcopyrite can be selectively flotated, and chalcopyrite and pyrite can be efficiently separated.

According to this method, the pH of the liquid phase of the mineral slurry may remain low. A small amount of pH adjuster is required, and the cost of the pH adjuster can be reduced. Moreover, it is not necessary to add an oxidizing agent such as hydrogen peroxide for the oxidation of pyrite. Therefore, the cost of the oxidizing agent can be reduced. In this way, the cost of the chemical required for suppressing the floating of pyrite can be reduced.

(4) Froth flotation process In the flotation process, flotation is performed using the mineral slurry after stirring. Froth flotation separates chalcopyrite as flotation and pyrite as sedimentation. More precisely, the raw material mineral contained in the mineral slurry is separated into a floating ore having a higher proportion of chalcopyrite than the raw material mineral and a submerged ore having a higher proportion of pyrite than the raw material mineral. The apparatus and method used for flotation are not particularly limited, and a general multi-stage flotation apparatus may be used.

Various gases can be used as the gas to be blown into the mineral slurry in the flotation. For example, when economic efficiency is prioritized, the atmosphere (air) is used. Further, in order to prevent the degree of oxidation of the mineral particles from changing, a gas containing no oxygen, for example, nitrogen is used. Conversely, oxygen is used to promote the oxidation of mineral particles. When sulfurizing mineral particles, sulfurous acid gas is used.

A flotation agent such as a catching agent, an inhibitor, and a foaming agent may be added to the mineral slurry. Sodium, zansate, ethyl zansate and the like can be used as the collecting agent. Gelatin, lactic acid, starch and the like can be used as the inhibitor. As the foaming agent, MIBC (methylisobutylcarbinol), pine oil, cresol acid and the like can be used. The flotation agent may be added to the mineral slurry in the flotation beneficiation step, or may be added to the mineral slurry in the stirring step. Further, a pH adjusting agent such as hydrochloric acid, hydrogen peroxide solution, caustic soda, or lime may be added to the mineral slurry to adjust the pH of the liquid phase of the mineral slurry.

As described above, the coexistence of iron ions promotes oxidation of the pyrite surface and suppresses the floating of pyrite. As a result, chalcopyrite and pyrite can be separated by flotation.

Further, by stirring the mineral slurry, it is possible to give a difference in the degree of oxidation between chalcopyrite and pyrite. Since chalcopyrite is not oxidized as compared with pyrite, it is easy for the inhibitor to adhere and float. On the other hand, since pyrite is more oxidized than chalcopyrite, hydrophilicity is maintained and the inhibitor is less likely to adhere. Therefore, chalcopyrite can be selectively suspended while sedimenting chalcopyrite, and chalcopyrite and pyrite can be efficiently separated.

Floating ore with a high proportion of chalcopyrite is further recovered as a concentrate through steps such as solid-liquid separation and washing. The obtained concentrate may be supplied to the stirring step. At this time, polishing may be performed to remove impurities adhering to the surface of the mineral particles. By repeating the stirring step and the flotation step, the purity of chalcopyrite can be further increased.

Next, an embodiment will be described.
(Stirring time)
Chalcopyrite samples and pyrite samples were prepared. The composition of the chalcopyrite sample is 80% by mass of chalcopyrite, 11% by mass of pyrite, 5% by mass of hematite (Fe ₂ O ₃ ), and 4% by mass of sphalerite (ZnS). The composition of the pyrite sample is 100% by mass of pyrite. Both the chalcopyrite sample and the pyrite sample have a particle size of 106 to 150 μm. Each mineral sample was washed with concentrated hydrochloric acid and acetone to remove oxides and sulfur coatings on the surface of the mineral particles.

300 mL of pure water was placed in a beaker having a capacity of 500 mL, and hydrochloric acid or sodium hydroxide was added as a pH adjuster to adjust the pH to 6 or 9. After adjusting the pH, 1.5 g of a chalcopyrite sample or a pyrite sample was added to prepare a mineral slurry. That is, four types of mineral slurries were prepared: a pH 6 chalcopyrite slurry, a pH 6 pyrite slurry, a pH 9 chalcopyrite slurry, and a pH 9 pyrite slurry. Sodium chloride was added to each mineral slurry to make the ionic strength of the aqueous phase 0.05, which corresponds to seawater.

Each mineral slurry was stirred with a magnetic stirrer (RS-6AN AS ONE, 1200 rpm, the same applies hereinafter). The dissolved oxygen concentration in the liquid phase of the mineral slurry during stirring was 7.0 mg / L. Every predetermined time elapsed from the start of stirring, 5 mL of the mineral slurry was collected with a 5 mL polypropylene syringe and filtered with a 0.1 μm syringe filter (manufactured by Nippon Pole). The filtrate was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-OES) to determine the Total-S concentration.

FIG. 1 (A) shows the time change of the Total-S concentration in the case of pH 6. FIG. 1 (B) shows the time change of the Total-S concentration in the case of pH 9. When the sulfide mineral is oxidized, sulfur is eluted in the liquid phase depending on the degree of oxidation. Therefore, the total-S concentration of the liquid phase indicates the degree of oxidation of the sulfide mineral. Further, the rate of increase in the Total-S concentration, that is, the slope of the graphs in FIGS. 1A and 1B means the oxidation rate of the sulfide mineral.

As can be seen from the graphs of FIGS. 1A and 1B, the oxidation of both pyrite and chalcopyrite progresses with the lapse of stirring time. It is considered that this is because the surface of the mineral particles is oxidized by the dissolved oxygen in the liquid phase.

In both pH 6 and pH 9, the oxidation rate of chalcopyrite (rate of increase in Total-S concentration) is constant for at least a stirring time of 250 minutes. On the other hand, the oxidation rate of pyrite is almost the same as the oxidation rate of chalcopyrite in the first half of stirring, but the oxidation rate becomes faster in the second half of stirring. That is, the oxidation rate of pyrite changes from low speed to high speed during stirring. The time point at which the oxidation rate of pyrite changes from low speed to high speed (change time point) is 150 minutes at pH 6 and 100 minutes at pH 9.

After the oxidation rate of pyrite changes at a high speed, pyrite can be made more oxidized than chalcopyrite. Moreover, the longer the stirring time, the greater the difference in the degree of oxidation between pyrite and chalcopyrite. Oxidation of pyrite produces hydrophilic ferric hydroxide on the surface of pyrite. In addition, this suppresses the adhesion of the catching agent to pyrite. Therefore, the hydrophilicity of pyrite is maintained, and flotation enables separation of chalcopyrite and pyrite.

From the viewpoint of giving a difference in the degree of oxidation between pyrite and chalcopyrite, the stirring time may be set to a time exceeding the time of change. In order to increase the difference in the degree of oxidation, it is preferable to continue stirring beyond the time of change. That is, the stirring time is preferably 10 minutes after the change, more preferably 20 minutes, and even more preferably 30 minutes.

If the stirring time is more than 150 minutes at least in the pH range of 6-9, the degree of oxidation can be different between pyrite and chalcopyrite. From the viewpoint of increasing the difference in the degree of oxidation, the stirring time is preferably 160 minutes or longer, more preferably 170 minutes or longer, and even more preferably 180 minutes or longer. It can be confirmed that there is a difference in the degree of oxidation at least in the range of stirring time up to 250 minutes.

(Elementary substance flotation test)
Chalcopyrite samples and pyrite samples were prepared. The composition and particle size of the chalcopyrite sample and the pyrite sample are as described above. Each mineral sample was washed with concentrated hydrochloric acid and acetone to remove oxides and sulfur coatings on the surface of the mineral particles.

Next, a solution used for producing the mineral slurry was prepared. Calcium chloride was added to pure water to prepare a solution having a calcium concentration of 100 mg / L. Next, ferric chloride was added to the solution as an iron source to adjust the iron concentration. Hereinafter, the solution to which no iron source is added (iron concentration 0 mg / L) is referred to as solution 1, the solution having an iron concentration of 10 mg / L is referred to as solution 2, and the solution having an iron concentration of 100 mg / L is referred to as solution 3. Solution 2 has Ca / Fe = 10 and solution 3 has Ca / Fe = 1. Hydrochloric acid or sodium hydroxide was added to each solution as a pH adjuster to adjust the pH to 9 or 12. In addition, sodium chloride was added to each solution to set the ionic strength to 0.05, which corresponds to seawater.

100 mL of the solution was placed in a beaker having a capacity of 200 mL, and 0.5 g of a chalcopyrite sample or a pyrite sample was added to prepare a mineral slurry. The mineral slurry was stirred with a magnetic stirrer. The dissolved oxygen concentration in the liquid phase of the mineral slurry during stirring was 7.0 mg / L. The stirring time was 180 minutes.

A flotation test was carried out by adding 10 μL of MIBC (methylisobutylcarbinol) as a foaming agent and 50 g / t (50 g per 1 ton of mineral) of PAX (potassium amylzansate) as a trapping agent to the mineral slurry.

The flotation tube shown in FIG. 2 was used for the flotation test. A stirrer is provided on the bottom of the Harimond tube to allow the liquid to be agitated. In addition, gas can be blown into the Harimond tube from the bottom.

The flotation test was carried out according to the following procedure. First, the mineral slurry was placed in a Harimond tube. Next, air was blown at a flow rate of 200 mL / min while stirring the liquid in the Harimond tube. The processing time was 1 minute. The suspended mineral particles settle in the anchorage in the middle of the Harimond tube. Mineral particles settled in the retaining part were used as floating ore. On the other hand, the mineral particles settled at the bottom of the Harimond tube were used as the settling.

Each of the recovered floating ore and subsidence was filtered and lyophilized before weighing. A syringe filter (manufactured by Nippon Pole) having a pore size of 0.1 μm was used for filtration. Based on the following formula (1), the floating ore ratio was calculated from the weight of floating ore.
Floating ore rate [mass%] = {(floating ore weight) / (floating ore weight + submerged ore weight)} × 100 ・ ・ ・ (1)

Table 1 shows the conditions of the mineral slurry and the floating ore ratio when the pH is 9. Table 2 shows the conditions of the mineral slurry and the floating ore ratio when the pH is 12. Further, using the results of the flotation test under the same pH, calcium concentration, and iron concentration, the flotation rate difference of chalcopyrite was obtained by subtracting the flotation rate of chalcopyrite from the flotation rate of chalcopyrite. The results are shown in Tables 1 and 2. The flotation rate difference indicates the ease of separation of chalcopyrite and pyrite in flotation beneficiation.

As can be seen from Table 1, in the case of pH 9, when the iron concentration is 0 mg / L, the difference in buoyancy rate is −8.8%. This means that pyrite is more likely to float than chalcopyrite. Moreover, since the absolute value of the difference in floating ore ratio is small, it is difficult to separate chalcopyrite and pyrite. On the other hand, when the iron concentration is 10 mg / L, the buoyancy rate difference is 63.0%, and when the iron concentration is 100 mg / L, the buoyancy rate difference is 42.6%. From this, it was confirmed that if iron is added to the mineral slurry, chalcopyrite and pyrite can be easily separated.

From Table 2, there is a similar tendency in the case of pH 12. When the iron concentration is 0 mg / L, the difference in buoyancy rate is 26.1%. On the other hand, when the iron concentration is 10 mg / L, the buoyancy rate difference is 71.7%, and when the iron concentration is 100 mg / L, the buoyancy rate difference is 59.8%. Therefore, it was confirmed that even in the case of pH 12, if iron is added to the mineral slurry, chalcopyrite and pyrite can be easily separated.

(Mixed flotation test)
A chalcopyrite sample and a pyrite sample were mixed at a weight ratio of 1: 1 to prepare a mixed sample. 100 mL of the solution was placed in a beaker having a capacity of 200 mL, and 0.5 g of the mixed sample was added to prepare a mineral slurry. The preliminary conditions and procedures are the same as for the elemental flotation test.

Each of the flotation and subsidence recovered in the flotation test was filtered and lyophilized before weighing. In addition, each of the floating ore and the subsidence was crushed in an agate mortar, dissolved in royal water, and the copper grade was measured by inductively coupled plasma emission spectrometry (ICP-OES) analysis. Based on the following formula (2), the actual copper yield was determined from the weight of floating ore and subsidence and the copper grade.
Actual copper yield [%] = {(Floating copper grade x Floating ore weight) / (Floating ore copper grade x Floating ore weight + Sinking copper grade x Sinking ore weight)} x 100 ... (2)

Table 3 shows the conditions of the mineral slurry and the actual copper yield.

As can be seen from Table 3, in the case of pH 9, the actual copper yield is 50.5% when the iron concentration is 0 mg / L. On the other hand, when the iron concentration is 100 mg / L, the actual copper yield increases to 75.8%. Further, in the case of pH 12, when the iron concentration is 0 mg / L, the actual copper yield is 51.5%. On the other hand, when the iron concentration is 10 mg / L, the actual copper yield increases to 61.4%. From the above, it was confirmed that chalcopyrite and pyrite can be easily separated by adding iron even in the mixed system.

Claims (5)

A mineral slurry manufacturing process in which mineral particles containing chalcopyrite and pyrite, water containing calcium, and an iron source are mixed to obtain a mineral slurry, and
A stirring step of stirring the mineral slurry and
A mineral processing method comprising: a flotation beneficiation step of performing flotation beneficiation using the mineral slurry after the stirring step. The mineral processing method according to claim 1, wherein the amount of the iron source added is such that the molar ratio of calcium ions to iron ions in the liquid phase of the mineral slurry is 1 to 10. The mineral processing method according to claim 1 or 2, wherein the stirring time in the stirring step is a time exceeding the time point at which the oxidation rate of pyrite changes from low speed to high speed. The mineral processing method according to claim 1 or 2, wherein the stirring time in the stirring step is more than 150 minutes. The mineral processing method according to any one of claims 1 to 4, wherein the liquid phase of the mineral slurry in the stirring step is pH 6 to 9.

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